The present invention relates generally to combustion tools and in particular to a device and a method for conserving battery power in combustion tools.
Combustion tools are known in the art for use in driving fasteners into workpieces, examples of which are described in Nikolich, U.S. Pat. Re. No. 32,452, and U.S. Pat. Nos. 4,522,162; 4,483,473; 4,483,474; 4,403,722; 5,197,646; 5,263,439 and 5,713,313, commonly assigned and incorporated by reference herein. Similar combustion-powered nail and staple driving tools are available commercially from ITW-Paslode of Vernon Hills, Ill. under the IMPULSE®, PASLODE®, and DUO-FAST® brands.
Combustion tools incorporate battery-powered elements, such as igniters, fans, and indicator lights. These battery-powered elements are driven by power supplied by an onboard battery and, to prolong battery life, it is common practice to remove the battery completely from the tool housing while the tool is not in use. While removing the battery is effective in prolonging battery life, users often forget to remove the battery. In these situations, the tool remains on and the battery is drained of power by such ancillary items as battery switches, indicator lights, and/or LEDs, which are typically configured to show the user that the tool is on, operational, functional, or has power.
Current solutions to the issue of battery power drainage include using sleep mode circuits within the tool. These sleep-mode circuits, which commonly use mechanical switches, place the tool in a sleep mode after a defined period of time. Mechanical switches, however, are subject to corrosion and wear, as well as shock and vibration, or fretting corrosion, reducing the long term effectiveness of such switches and sleep mode circuits. In addition, often it is necessary to “prime” the tool (for example, press a trigger or press the nose of the tool to a substrate) in order to wake up the tool from the sleep mode prior to the tool being useful for subsequent actuation or operation.
Accordingly, there is a need for a solution to battery drainage that minimizes battery consumption to prolong performance and battery life while allowing quick and timely actuation of the device when necessary.